The invention relates to a process for producing agglomerates from fine-grained iron carriers, in particular iron ores and/or iron-containing dusts and/or slurries, and at least one binder as a charge material for a thermal process, in particular a metallurgical process, wherein the iron carriers are mixed with the binder and any additions and agglomerated.
The invention also relates to a process for producing liquid pig iron or liquid primary steel products from charge materials, in particular iron ores, possibly additions and agglomerates, wherein the charge materials are subjected to a substantial reduction in a reducing zone and then fed to a smelting zone or a smelting unit, in particular a melt gasifier, for smelting with the addition of carbon carriers and oxygen-containing gas to form a fixed bed, and a reducing gas is formed and introduced into the reducing zone.
WO 2005/103307A discloses a method for the production of layered iron ore balls. It is suggested to add an internal fuel additive to the outer layer.
JP 3-36219 discloses a method for the production of layered pellets with necessary strength and little powderization. The outer layer has a higher Bentonite ratio compared to the inner layer.
A method for the production of Chromium ore pellets can be derived from JP 54-62913. In order to increase the strength of the pellets it is suggested to coat the pellets with a layer of ferronickel slag powder.
U.S. Pat. No. 4,701,214 A teaches a method for the production of iron from finely divided iron ore. The iron ore fines are agglomerated, prereduced in a rotary hearth furnace and charged into a smelting-reduction vessel together with carbon carriers and oxygen where iron is produced. In the smelting-reduction vessel a CO- and H2-containing reduction gas is formed which is introduced into the rotary hearth furnace for the reduction of the agglomerates.
It is known from the prior art that fine ores are initially reduced in reducing zones and then smelted in a smelting zone to form pig iron. Such processes operate in an operating range which is characterized for example by the grain size of the charge materials. In principle, small grain sizes entail the problem that considerable amounts of dust occur in the process or small particles can be discharged from the process units along with the process gas.